This grant will develop, validate, and utilize novel protocols for rapid generation of molecular probes. The generation of molecular probes (usually monoclonal antibodies) remains a critical bottleneck in biomedical research, biomarker discovery, and diagnostic test development. Several approaches have been developed to overcome this problem. For example, yeast display libraries express diverse single chain-fragment variable (scFv) antibodies on the surfaces of Saccharomyces cerevisiae cells. By using fluorescent-activated cell sorting (FACS), yeast clones that bind specifically to antigens can be selected from naive libraries in 2 to 3 weeks. However, selected probes that perform well on yeast cell surfaces often perform poorly in solution. In order to achieve a more broadly useful, accelerated pipeline for molecular probes, this grant will leverage the speed and throughput of yeast scFv display, while overcoming its innate limitations. A yeast immunoprecipitation - tandem mass spectroscopy (yeast IP-MS/MS) approach will be used to improve the speed and throughput of biomarker research. Novel nanoparticle scaffolds combined with FACS will be used to improve the functional affinity of scFv binding to antigens. As a model for the development of these approaches, the project will identify novel cyst antigens of Entamoaeba histolytica, an important enteric pathogen and Category B agent. The accelerated molecular probe pipeline (AMPP) will be used first to identify and validate these biomarkers, and then to generate high-activity scFv probes for incorporation into an improved diagnostic test for E. histolytica cysts in stool. RELEVANCE (See instructions): If successful, this project will change the way molecular probes are generated for research, biomarker discovery, and diagnostic testing. It will benefit any research or development effort that utilizes molecular probes, and pave faster routes to new vaccines, drugs, and diagnostics.